Suction cleaner



1956 c. E. s. ANDERssoN-sAsoN ETAL 3,279,157

SUCTION CLEANER 2 Sheets-Sheet 1 Filed Jan. 15, 1963 Oct. 18, 1966 c. E. s. ANDERSSON-$ASON ETAL 3,

SUCTION CLEANER Filed Jan. 15. 1965 2 Sheets-Sheet 2 l '1" 1| II II H II n u /2 22 22 j/ II "I" II II u If ,1 ii u u *1 lnl' jg 366 United States Patent 3,279,157 SUCTlON CLEANER Carl Erik Sixten Andersson-Sason, Solna, and Ture Emanuel Lindahl, li-lagersten, Sweden, amignors to Aktiebolaget Electrolux, Stockholm, Sweden, :1 corporation of Sweden Filed Jan. 15, 1963, Ser. No. 251,604 Claims priority, application Sweden, Jan. 19, 1962, 601/62 6 Claims. (Cl. 55-357) Our invention relates to suction cleaners.

Suction cleaners comprise a casing having an air inlet and outlet and a motor-fan unit for moving air in a path of flow therethrough. A removable dust bag is located in the casing adjacent the air inlet for separating entrained dust from the air flowing through the casing. A fine filter often is provided adjacent the air outlet of the casing to insure removal of any fine dust particles which may have passed through the dust bag before the air is discharged into the room. Also, a suction cleaner accessory is often detachably connected to the air outlet or blowing outlet end of the casing. The accessory may be a hose, or a spraying device which is connected to one end of a hose, the opposite end of which is connected to the cleaner outlet.

The object of our invention is to provide an improved suction cleaner of the type indicated in which apertured structure defining an air discharge opening or blowing outlet end, which is formed to detachably receive an end of the hose, is concealed from view by a fine air filter during normal operation of the cleaner for suction purpose and can readily be made available for use when desired. We accomplish this by providing a suction cleaner casing having a longitudinally extending exterior wall section which is movable lengthwise of the casing to and from a first position over the air discharge opening or blowing outlet end and a fine filter comprising a layer of air-permeable material which has a cross-sectional area greater than the air discharge opening or blowing outlet end, and, when the motor-fan unit is employed to induce flow of air by suction effect into the dust bag to collect dust therein and the longitudinally movable exterior wall section is in its first position, the fine air filter is adjacent to the inner surface of the movable exterior wall section and disposed in the path of air flow between the air discharge opening or blowing outlet end and the outer surface of the exterior wall section, whereby air discharged from the air discharge opening or blowing outlet end will flow through the fine filter to the exterior of the casing past the longitudinally movable exterior wall section which, when it is in its first position, defines the air outlet of the suction cleaner.

Further objects and advantages of the invention will become apparent as the following description proceeds,

. and the features of novelty which characterize the invention will be pointed out with particularity in the claims annexed to and forming a part of this specification.

For a better understanding of the invention, reference may be had to the following description taken in connection with the accompanying drawings, in which:

FIG. 1 is a side elevational view, partly broken away and in section, of a suction cleaner embodying the invention;

FIG. 2 is a fragmentary top plan view of the cleaner shown in FIG. 1;

FIG. 3 is a view similar to FIG. 2 illustrating the mannet in which access is gained to the blowing outlet end of the cleaner; and

FIG. 4 is a sectional view taken at line 44 of FIG. 1.

' Referring to the drawing, the invention has been shown in connection with a horizontal tank-type suction cleaner Patented Oct. 18, 1966 "ice 10 having a casing 11 including a top 12, bottom 14 and vertically extending side walls 15. The casing 11 is provided with a handle 16 and spaced members 17 which extend lengthwise of the casing along the bottom 14 and serve as skids to facilitate movement of the cleaner on a surface.

A front end cover 18 is removably secured at 19 to the casing 11 in any suitable manner and formed with an inlet opening 20 to which a suction hose (not shown) is adapted to be removably connected. Suitable cleaning appliances may be connected to the outer free end of the suction hose and through which air flows into the casing. Within the casing 11 is provided a perforated partition 21, at one side of which is disposed a removable dust collector or dust bag 22 which acts to separate dust from air as it flows therethrough.

Flow of air through casing 11 is effected by a motor-fan unit 23 which includes a centrifugal fan 24 carried at one end of an electric motor 25. The motor-fan unit 23 is suspended in casing 11 by structure 26 which provides a resilient mounting for the motor-fan unit and a seal between spaces 27 and 28 in the casing, the inner and outer peripheries of the suspension structure being respectively fixed to the motor-fan unit 23 and an inwardly extending flange 29 of the casing. A switch 30 is located at the top of a rear hood or end cover 32 which is removably secured in any suitable manner (not shown) to the casing 11. The switch 30 is provided with an actuating button 31 which extends upward through an opening in the end cover 32 and is accessible at the exterior of the casing 11. The switch 30 forms part of an electrical circuit (not shown) for respectively connecting and disconnecting the motor 25 to and from a source of electrical energy in any manner well known in the art.

When the suction cleaner 10 is being operated and the fan 24 driven by the motor 25, dust-laden air is drawn through the suction hose into the interior of the casing 11. Dust collects in the bag 22, and airfrom which dust has been removed passes through the dust bag and perforated partition 21 into the space 27. Air in the space 27 flows into the inlet 24' of the fan 24 from which it is discharged and flows through the shell of the motor 25 to effect cooling thereof, such air passing from the motor at 33 into the space 28 defined in part by the suspension structure 26 which bridges the gap between the motor-fan unit23 and the flange 29. In this way the passage formed between the casing 11 and the motor-fan unit 23 is closed by the suspension structure 26 and all of the air discharged from the fan 24 passes throughthe motor 25 into the space 28.

The space 28 is also defined in part by a partition 32a which is transverse to the axis c--c of the casing 11 and is impervious to air and fixed to the casing ll in any suitable manner toform a seat at the end thereof in which a part 32b of the rear end cover 32 nests when it is mounted on the casing. The end cover 32, which is cupshaped, and transverse partition 32a form a compartment 320 in which the switch 30 is located. When the rear end cover 32, which is removed axially of the casing 11 from an air outlet 36d, is removed from the casing 11 to repair the switch 30 or provide a new one for the cleaner 10, for example, the transverse partition 32a remains in its mounted position on the casing 11 so that contact with the motor 25 is prevented. In. its mounted position all points of the periphery of the wall 32a conaxially of the casing 11 and is disposed above the openings 33 from which air emerges from the motor shell and overlies one end of the motor-fan unit at which it is journaled at 23'. It will now be seen that the casing 11 forms a single housing for the dust bag 22 and motor-fan 'unit 23 which are disposed alongside one another and have a common longitudinal axis c-c extending lengthwise of the cleaner 10. The vertical axis dd of the air discharge opening 34 is substantially perpendicular to the longitudinal axis cc of the dust bag 22 and motorfan unit 23 so that all of the air emerging from the openings 33 of the motor shell into the space 28 will flow therefrom to the top part 12a of the casing 11 and be discharged upward therefrom through the opening 34. However, the compartment 320 formed by the end cover 32 and transverse wall 32a is axially removed from and outside of that part of the casing 11 providing the path of flow for air between the inlet 20 and outlet 36d.

A suction cleaner accessory is often detachably connected to the air discharge opening 34 of the cleaner. The accessory may be a hose, or a spraying device which 1s connected to one end of the hose, the opposite end of which is connected to the air discharge opening 34. Such accessories are usually provided with fittings which are of a kind well known in the art and enable them to be detachably connected to the opening 34.

In accordance with this invention, a very fine filter 35 is provided at the top wall 12 of the casing 11 which overlies the air discharge opening 34 and is movable axially over the outer surface of the casing 11 to permit 'a suction cleaner accessory to 'be detachably connected to the air discharge opening. The filter 35 may comprise a single sheet of material, such as cloth, paper or the like, for example, 'which is formed of fibrous material which is permeable to air and impregnated or bonded with a plastic like polyacrylonitrile butadiene-styrene, for example. The filter 35 is mounted at the underside of an apertured filter frame or member 36 having a reticulated grill defined by spaced axially extending ribs 36a and transverse ribs 36b.

As seen in FIG. 4, the filter 35 and frame 36 upon which it is mounted are slightly arched and conform to the shape of the top wall 12 of the casing 11. However, the filter 35 is essentially fiat and closely adjacent to the top 12 of the casing 11. The filter frame 36 also may be formed of a plastic like polyacrylonitrile butadiene-styrene, for example. When a plastic of this type is employed to provide the member or frame 36, it may be formed by compression molding in suitable dies in which the filter 35 is positioned, whereby the filter and frame 36 become an integral structure with the filter and frame bonded to one another. In FIG. 4 it will be seen that the filter 35 is fixed to the underside or bottom of the frame 36 and the ribs 36a and 36b project vertically 'upward therefrom. The intersecting spaced ribs 36a and 36b provide openings 36c which collectively define the air outlet 36d.

The filter frame 36 is received and held at the top 12 of the casing 11 by means 37, the frame 36 being movable "lengthwise or axially of the casing 11 by the means 37 which comprise spaced guides or tracks 37a fixed to the top 12 of the casing in any suitable manner. The tracks 37a are formed with U-shaped channels 38, the open ends of which face one another and receive the outermost axially extending ribs 36a of the frame 36. The top parts of the tracks 37a, which form the upper arms 38a of the channels 38, overlie the top edges of the outermost axially extending ribs 36a and form grooves in which the filter frame 36 is movable lengthwise of the casing 11.

As best shown in FIGS. 2 and 3, the handle 16 and spaced tracks 37a may comprise an integral part formed of a suitable plastic. The handle 16 includes a pair of spaced sides 16a each of'which extends vertically upward from a different one of the tracks 37a. The handle 16 further includes a crossbar 16b which is connected to the of the casing 11, as shown in FIG. 2. When it is desired to connect a suction cleaner accessory to the air discharge opening 34 of the cleaner, the filter frame 36 is moved lengthwise of the casing 11 beneath the handle 16 so that the air discharge opening 34 will be accessible, as shown in FIG. 3. In FIG. 3 it will be seen that the lefthand end of the filter frame 36 is notched at 40. When the filter frame 36 is moved to its normal closed position seen in FIG. 2, the notched ends 40 of the filter frame move against shoulders 41 on the tracks which frictionally grip the left-hand end of the frame 36 and serve as stops to limit axial movement of the frame.

The fine filter 35 serves to remove fine dust particles from air emerging from the opening 34. The air-permeable filter 35 preferably is microporous in character and also serves as a diffuser. For this reason the fine filter 35 normally is positioned at the vicinity of the top 12 of casing 11 at a level which is above the air discharge opening 34 to provide a diffusing chamber 42 at the underside of the filter. During normal operation of the cleaner 10 air fiows through the opening 34 at a relatively high veloc ity. The filter 35 has an overall cross-sectional area that is materially greater than that of the air discharge opening 34, whereby the air is subdivided into a multiplicity of tiny air streams which are discharged from the outer surface of the filter 35 over its entire area which is sufficient to reduce the velocity of the air discharged from the cleaner so that settled dust in the vicinity of the cleaner will not be disturbed.

As seen in FIG. 1, a plate 43 is fixed to the imperforate transverse wall 32a and extends axially of the casing 11 at a zone between the motor 25 and air discharge opening 34. Air passing from space 28 to the opening 34 flows around the plate 43 which serves as a protective shield to prevent current-carrying parts of the motor circuit from being contacted when the filter frame 36 is moved to its open position shown in FIG. 3 and the air discharge opening 34 of the cleaner is exposed.

In view of the foregoing, it will now be understood that the frame 36 and filter layer 35 mounted on the inner side thereof form an exterior wall section of the casing 11. During normal operation of the cleaner for cleaning purpose, the filter layer 35 is mounted over the opening 34 in a plane which is substantially perpendicular to the vertical axis dd of the opening and in the path of air flow between the opening 34 and the outer surface of the apertured movable exterior wall section 36 which defines the air outlet of the suction cleaner when positioned over the opening 34. With this construction air discharged vertically upward from the opening 34 will flow through the filter layer 35 and past the exterior wall section 36 to the exterior of the casing 11 at which region the air outlet 36d is located.

It will now be understood that the fine air filter 35 is disposed between the motor-fan unit 23, which is horizontally disposed in the casing 11, and the air outlet 36d of the cleaner which is defined by the apertured member 36 when the latter, which serves as an exterior Wall section of the casing 11, is in its first or closed position over the air discharge opening 34, as shown in FIG. 1.

The portion of the path of flow of air between the motor-fan unit 23 and the fine air filter 35 includes the in FIG. 1, the fine air filter 35 is positioned between the opening 34 and the outer surface of the exterior wall section 36 for air discharged from the opening 34 to flow through the fine air filter 35, which is in intimate physical contact with the inner surface of the exterior wall section 36 during operation of the cleaner, and past the exterior wall section to the exterior of the casing 11.

While a particular embodiment of the invention has been shown and described, such variations and modifications are contemplated as fall within the true spirit and scope of the invention, as pointed out in the following claims.

We claim:

1. In a tank-type suction cleaner having, in combination,

(a) an elongated casing (11) which normally is horizontally disposed and provided with an air inlet and an outlet (36d) and having a path of flow for air therebetween (20 and 36d), the air outlet (36d) being at the top (12) of said casing (11), the air inlet (20) and outlet (36d) being located at opposite ends of said elongated casing (11) and removed from one another axially (c-c) of said casing (11),

(b) said casing (11) including an imperforate wall (32a) which is transverse to the axis (c-c) of said casing (11), said wall (32a) having all points of the periphery thereof contacting the interior surface of said casing (11) in sealing engagement therewith and defining a part of the path of flow for air between the inlet (20) and the outlet (36d) which is at the top (12) of the casing (11),

(c) means extending axially (0-0) in said casing (11) and including a motor-fan unit (23) for circulating air in the path of flow from the inlet (20) to the outlet (36d), said unit (23) including an electric motor and a fan (24) driven thereby, said motor (25) and said fan (24) being disposed within said path of flow,

(d) means including structure (26, 29) to provide sealing means (26, 29) between said casing (11) and said motor-fan unit (23) for constraining all air passing through said path of flow to flow through said motor-fan unit (23),

(e) said casing (11) having a compartment (320) which is outside the path of flow for air between said inlet (20) and the outlet (36d), switch means (30) in said compartment (320) for controlling said motor (25), said switch means (30) having a control member (31) which extends to the exterior of said casing 11) and is accessible at the top (12) thereof, said compartment (320) being defined in part by an exterior wall part (32) of said casing (11) which is removable therefrom for inspecting said switch means (30) without disturbing said motor (25) in said path of flow for air between said inlet (20) and outlet (f) wall means including a part (12a) at the top (12) of said casing (11) and said transverse wall (32a) and said sealing means (26, 29) defining a space (28) which forms a part of said path of flow for air between the inlet (20) and outlet (36d) and into which all of the air flows through said motor-fan unit (23),

(g) said part (1211) at the top (12) of said casing (11) being formed with an opening (34) having a vertical axis (d-d), said opening (34) being below and vertically spaced from the outlet (36d) and through which air from said space (28) in its path of flow from the inlet (20) to the outlet (36d) is discharged vertically upward toward the outlet (36d),

(h) an air filter comprising a layer (35) of air-permeable material having a cross-sectional area greater than that of the air discharge opening 34) (i) the top (12) of said casing (11) including an exterior wall section (36) which is apertured (36c) and movable to and from a position over the opening (j) the outlet (36d) of the cleaner (10) being defined by said exterior wall section (36) when positioned over the opening (34),

(k) the opening (34) being formed to receive an end of a hose and being accessible when said exterior wall section (36) is moved from its position over the opening (34),

(1) means (37) which functions to receive and hold said exterior wall section (36) over the opening (34), said last-mentioned means (37) functioning to enable said exterior wall section (36) to be moved to and from its position over the opening (34),

(m) and said layer (35) of air-permeable material during operation of the cleaner being maintained over the opening (34) and in a horizontally extending plane which is substantially perpendicular to the vertically extending axis (dd) of the opening (34) and between the opening (34) and the outer surface (36e) of said exterior wall section (36) for air discharged upward from the opening (34) to fiow through said layer (35) of air-permeable material and past said exterior wall section (36) to the exterior of said casing (11).

2. In a tank-type suction cleaner (10) as set forth in claim 1 in which said means (37) to receive and hold said exterior wall section (36) over the opening (34) comprises spaced tracks (37a) extending axially (cc) of said casing (11) at the top (12) thereof, said tracks (37a) being U-shaped (38) in transverse section and having their open ends facing one another, and said exterior wall section (36) being slidable axially (c-c) of said casing 11) along said tracks (37a).

3. In a tank-type suction cleaner (10) as set forth in claim 2 which includes a handle (16) having a pair of spaced sides (16a) each of which extends vertically upward from a different one of said tracks (37a) and a crossbar (16b) connected to the upper ends of said sides (16a), said crossbar (1612) being spaced from the top (12) of saidcasing (11) and substantially perpendicular to the axis (c c) of said casing (11), and said exterior wall section (36) being slidable axially (cc) of said casing (11) along said tracks (37a) from a first position over said opening (34) to a second position removed from said opening (34) in which at least a part of said exterior wall section (36) is beneath the crossbar (16b) of said handle (16).

4. In a tank-type suction cleaner (10) as set forth in claim 1 in which said exterior wall section (36) comprises an apertured frame (36a and 36b) and said. layer (35 of air-permeable material.

5. In a tank-type suction cleaner (10) as set forth in claim 4 in which said layer (35) of air-permeable material is in intimate physical contact with the inner surface of said exterior wall section (36).

6. In a tank-type suction cleaner (10) having, in combination,

(a) an elongated casing (11) which normally is horizontally disposed and provided with an air inlet (20) and an outlet (36d) and having a path. of flow for air therebetween (20 and 36a), the air outlet (36d) being at the top (12) of said casing (11), the air inlet (20) and outlet (3601) being located at opposite ends of said elongated casing (11) and removed from one another axially (cc) of said casing (b) said casing (11) including a hollow cup-shaped removable end cover (32) at the air outlet (36d) end thereof, said end cover (32) being removed axially (c--c) of said casing (11) from the air outlet (c) said casing (11) including an imperforate wall (32a) which is transverse to the axis (0-0) of said casing (11), said wall (32a) having all points of the periphery thereof contacting the interior surface of said casing (11) in sealing engagement therewith and '3 defining a part of the path of flow for air between the inlet (20) and the outlet (36d),

(d) said end cover (32) extending axially (c-c) of said casing (11) from said transverse wall (32a), and, together with said transverse wall (32a), forming a compartment (320) of said casing (11) which is axially removed from and outside of that part of said casing (11) providing the path of flow for air between the inlet (20) and outlet (36d),

(e) means extending axially (-0) in said casing (11) and including a motor-fan unit (23) for circulating air in the path of flow from the inlet to the outlet (36d), said unit (23) including an electric motor and a fan (24) driven thereby, said motor (25) and said fan (24) being disposed within said path of flow,

(f) switch means disposed in said compartment (320) within said end cover (32) for controlling said motor (25),

(g) means including structure (26, 29) to provide sealing means (26, 29) between said casing (11) and said motor-fan unit (23) for constraining all air passing through said path of flow to flow through said motor-fan unit (23),

(h) wall means including a part (12a) at the top (12) of said casing (11) and said transverse wall (32a) and said sealing means (26, 29) defining a space (28) which forms a part of said path of flow for air between the inlet (20) and outlet (36d) and into which all of the air flows through said motor-fan unit (23),

(i) said part (12a) at the top (12) of said casing (11) being formed with an opening (34) having a vertical axis (d-d), said opening (34) being below and vertically spaced from the outlet (36d) and through which air from said space (28) in its path of flow from the inlet (20) to the outlet (36d) is discharged vertically upward toward the outlet (36d), the air discharge opening (34) being formed to detachably receive an end of a hose,

(j) said casing (11) including an exterior wall section (36) at the top (12) thereof which is movable to and from a position over the air discharge opening (34), said exterior wall section being apertured (36c) and defining the air outlet (36d) of the cleaner (10) when positioned over the discharge opening (34),

(k) an air filter comprising a layer of air-perme- '8 able material having a cross-sectional area greater than that of the air discharge opening (34),

(l) and said air filter and exterior Wall section (36) being so constructed and formed that said layer (35) of air-permeable material defining said air filter, during normal operation of the cleaner (10) for cleaning purpose, is maintained over the air discharge opening (34) in a plane which is substantially perpendicular to the vertical axis (d-d) of the air dis charge opening (34) and between the opening (34) and the outer surface (36e) of said exterior wall sec tion (36) and air discharged from the opening (34) will flow through said layer (35) of air-permeable material defining said air filter and past said aperture (360) exterior wall section (36) to the exterior of said casing (11).

References Cited by the Examiner UNITED STATES PATENTS 1,134,294 4/1915 Supanz -473 1,954,924 4/1934 Engberg et al. 55-473 X 2,057,568 10/1936 Gerard 55-481 2,061,535 11/1936 Davies 55-481 X 2,244,843 6/1941 Lofgren 55-504 2,318,088 5/1943 Martinet 55-379 X 2,444,809 7/1948 Cranmer 55-372 X 2,507,672 5/1950 McAllister 55-472 X 2,651,383 9/1953 Yonkers 55-413 X 2,699,838 1/1955 Hansen 55-472 X 2,714,426 8/1955 White 15-327 X 2,757,753 8/1956 Kasper 55-314 2,814,065 11/1957 I-Iurd 15-330 3,002,215 10/1961 MacFarland 15-327 7 3,048,960 8/1962 Ohlson 55-372 3,150,403 9/1964 Nilsson 15-327 3,172,743 3/1965 Kowalewski 55472 X FOREIGN PATENTS 1,102,203 5/1955 France.

415,405 8/ 1934 Great Britain. 757,185 9/1956 Great Britain. 862,753 3/1961 Great Britain.

HARRY B. THORNTON, Primary Examiner. D. TALBERT, Assistant Examiner. 

1. IN A TANK-TYPE SUCTION CLEANER (10) HAVING, IN COMBINATION, (A) AN ELONGATED CASING (11) WHICH NORMALLY IS HORIZONTALLY DISPOSED AND PROVIDED WITH AN AIR INLET (20) AND AN OUTLET (36D) AND HAVING A PATH OF FLOW FOR AIR THEREBETWEEN (20 AND 36D), THE AIR OUTLET (36D) BEING AT THE TOP (12) OF SAID CASING (11), THE AIR INLET (20) AND OUTLET (36D) BEING LOCATED AT OPPOSITE ENDS OF SAID ELONGATED CASING (11) AND REMOVED FROM ONE ANOTHER AXIALLY (C-C) OF SAID CASING (11), (B) SAID CASING (11) INCLUDING AN IMPERFORATE WALL (32A) WHICH IS TRANSVERSE TO THE AXIS (C-C) OF SAID CASING (11), SAID WALL (32A) HAVING ALL POINTS OF THE PERIPHERY THEREOF CONTACTING THEINTERIOR SURFACE OF SAID CASING (11) IN SEALING ENGAGEMENT THEREWITH AND DEFINING A PART OF THE PATH OF FLOW FOR AIR BETWEEN THE INLET (20) AND THE OUTLET (36D) WHICH IS AT THE TOP (12) OF THE CASING (11), (C) MEANS EXTENDING AXIALLY (C-C) IN SAID CASING (11) AND INCLUDING A MOTOR-FAN UNIT (23) FOR CIRCULATING AIR IN THE PATH OF FLOW FROM THE INLET (20) TO THE OUTLET (36D), SAID UNIT (23) INCLUDING AN ELECTRIC MOTOR (25) AND A FAN (24) DRIVEN THEREBY, SAID MOTOR (25) AND SAID FAN (24) BEING DISPOSED WITHIN SAID PATH OF FLOW, (D) MEANS INCLUDING STRUCTURE (26,29) TO PROVIDE SEALING MEANS (26, 29) BETWEEN SAID CASING (11) AND SAID MOTOR-FAN UNIT (23) FOR CONSTRAINING ALL AIR PASSING THROUGH SAID PATH OF FLOW OF FLOW THROUGH SAID MOTOR-FAN UNIT (23), (E) SAID CASING (11) HAVING A COMPARTMENT (32C) WHICH IS OUTSIDE THE PATH OF FLOW FOR AIR BETWEEN SAID INLET (20) AND THE OUTLET (36D), SWITCH MEANS (30) IN SAID COMPARTMENT (32C) FOR CONTROLLING SAID MOTOR (25), SAID SWITCH MEANS (30) HAVING A CONTROL MEMBER (31) WHICH EXTENDS TO THE EXTERIOR OF SAID CASING (11) AND IS ACCESSIBLE AT THE TOP (12) THEREOF, SAID COMPARTMENT (32C) BEING DEFINED IN PART BY AN EXTERIOR WALL PART (32) OF SAID CASING (11) WHICH IS REMOVABLE THEREFROM FOR INSPECTING SAID SWITCH MEANS (30) WITHOUT DISTURBING SAID MOTOR (25) IN SAID PATH OF FLOW FOR AIR BETWEEN SAID INLET (20) AND OUTLET (36D), (F) WALL MEANS INCLUDING A PART (12A) AT THE TOP (12) OF SAID CASING (11) AND SAID TRANSVERSE WALL (32A) AND SAID SEALING MEANS (26,29) DEFINING A SPACE (28) WHICH FORMS A PART OF SAID PATH OF FLOW FOR AIR BETWEEN THE INLET (20) AND OUTLET 36D) AND INTO WHICH ALL OF THE AIR FLOWS THROUGH SAID MOTOR-FAN UNIT (23), (G) SAID PART (12A) AT THE TOP (12) OF SAID CASING (11) BEING FORMED WITH AN OPENING (34) HAVING A VERTICAL AXIS (D-D), SAID OPENING (34) BEING BELOW AND VERTIALLY SPACED FROM THE OUTLET (36D) AND THROUGH WHICH AIR FROM SAID SPACE (28) IN ITS PATH OF FLOW FROM THE INLET (20) TO THE OUTLET (36D) IS DISCHARGED VERTICALLY UPWARD TOWARD THE OUTLET (36D), (H) AN AIR FILTER COMPRISING A LAYER (35) OF AIR-PERMEABLE MATERIAL HAVING A CROSS-SECTIONAL AREA GREATER THAN THAT OF THE AIR DISCHARGE OPENING (34), (I) THE TOP (12) OF SAID CASING (11) INCLUDING AN EXTERIOR WALL SECTION (36) WHICH IS APERTURED (36C) AND MOVABLE TO AND FROM A POSITION OVER THE OPENING (34), (J) THE OUTLET (36D) OF THE CLEANER (10) BEING DEFINED BY SAID EXTERIOR WALL SECTION (36) WHEN POSITIONED OVER THE OPENING (34), (K) THE OPENING (34) BEING FORMED TO RECEIVE AN END OF A HOSE AND BEING ACCESSIBLE WHEN SAID EXTERIOR WALL SECTION (36) IS MOVED FROM ITS POSITION OVER THE OPENING (34), (L) MEANS (37) WHICH FUNCTIONS TO RECEIVE AND HOLD SAID EXTERIOR WALL SECTION (36) OVER THE OPENING (34), SAID LAST-MENTIONED MEANS (37) FUNCTIONING TO ENABLE SAID EXTERIOR WALL SECTION (36) TO BE MOVED TO AND FROM ITS POSITION OVER THE OPENING (34), (M) AND SAID LAYER (35) OF AIR-PERMEABLE MATERIAL DURING OPERATION OF THE CLEANER BEING MAINTAINED OVER THE OPENING (34) AND IN A HORIZONTALLY EXTENDING PLANE WHICH IS SUBTANTIALLY PERPENDICULAR TO THE VERTICALLY EXTENDING AXIS (D-D) OF THE OPENING (34) AND BETWEEN THE OPENING (34) AND THE OUTER SURFACE (36E) OF SAID EXTERIOR WALL SECTION (36) FOR AIR DISCHARGED UPWARD FROM THE OPENING (34) TO FLOW THROUGH SAID LAYER (35) OF AIR-PERMEABLE MATERIAL AND PAST SAID EXTERIOR WALL SECTION (36) TO THE EXTERIOR OF SAID CASING (11). 